One very common task in construction, welding, woodworking, plastic fabrication, ship building, and in general any material fabrication process is joining different elements together. Sometimes, such as when gluing wood elements together, long term pressure is required. At other times large, complex, and expensive fabrication facilities are required to properly align elements before joining. In certain cases various elements must be spread apart before elements can be properly fabricated. In almost all cases whenever discrete elements are being joined some type of spatial fixing is required.
Because of the wide variety of elements that must be joined or separated, a variety of devices are available to assist those processes. For example, the common “C” clamp is readily available in a wide range of sizes, from sub-inch maximum openings to well over 12″. “C” clamps are available and suitable for wood-working, welding, and general assembly use and they can be used in a remarkable number of ways. While “C” clamps are very useful, they have practical limitations on their throat size maximum openings, depth of clamp, weight in larger sizes, and cost. Furthermore, “C” clamps can be difficult and time-consuming for one person to use, and cannot be used for spreading elements. However, their most common drawback is that they take two hands to use. Properly spatially locating and holding multiple elements while requiring two hands to clamp the multiple elements together can be a major challenge.
Because of the limitations of the “C” clamp other clamps are available. For example, bar clamps. A bar clamp is a clamping device consisting of a long rod, tube, bar, or other elongated member (generically referred to hereinafter for convenience and reading clarity simply as a rod), a fixed jaw on the rod, and a moving adjustable clamping jaw. In different configurations the moving jaw can be moved toward or away from the fixed jaw or the rod can be moved relative to the moving jaw. Some bar clamps can be used with only one hand, which greatly facilities their use. Bar clamps are available in configurations in which a jaw is reversible. This facilities their use as spreaders.
Examples of bar clamps include those taught in U.S. Pat. No. 6,382,608 to Mitchell, entitled, “Adjustable Clamping and Spreading Bar Clamp or Bench Vice,” issued on May 7, 2002; U.S. Pat. No. 6,338,475 to Ping, entitled, “Bar Clamp,” issued on Feb. 12, 2001; and U.S. Pat. No. 7,159,858, to Ben-Gigi, entitled “Bar Clamp,” issued on Jan. 9, 2007. Examples of currently available bar clamps in different lengths are from Larin™, Craftsman™, Sears™, Pro-Grade™ and many others. Thus bar clamps and their ratcheting mechanisms are well known and commonly used.
While bar-clamps are widely used and have proven to be very useful, in some cases the maximum distance between the materials being joined is simply greater than the bar clamp can reach. Furthermore, as the distance between materials being joined increases the torques and other mechanical forces required to hold the materials rigid increase. Another major problem is that to span a wide range of distances either different bar clamps are required or a very long bar clamp that may be unwieldy for shorter applications is required.
Accordingly, there exists a need for a rigid, strong extended bar clamp/spreader that is suitable for one hand use over a wide span without being unwieldy. Beneficially such a bar clamp/spreader is suitable for low cost fabrication using efficient fabrication techniques.